[llvm] 6ba6351 - [PostOrderIterator] Use SmallVector to store stack; NFC

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2020-03-29T14:29:02+02:00
New Revision: 6ba63510720f5bd6033a3eeffd51f8d7e0e90432

URL: https://github.com/llvm/llvm-project/commit/6ba63510720f5bd6033a3eeffd51f8d7e0e90432
DIFF: https://github.com/llvm/llvm-project/commit/6ba63510720f5bd6033a3eeffd51f8d7e0e90432.diff

LOG: [PostOrderIterator] Use SmallVector to store stack; NFC

We use a SmallPtrSet to track visited nodes, use a SmallVector
of the same size for the stack.

Added: 
    

Modified: 
    llvm/include/llvm/ADT/PostOrderIterator.h

Removed: 
    


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diff  --git a/llvm/include/llvm/ADT/PostOrderIterator.h b/llvm/include/llvm/ADT/PostOrderIterator.h
index 2fe7447a8e77..bb413a956d9f 100644
--- a/llvm/include/llvm/ADT/PostOrderIterator.h
+++ b/llvm/include/llvm/ADT/PostOrderIterator.h
@@ -18,6 +18,7 @@
 #include "llvm/ADT/GraphTraits.h"
 #include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/iterator_range.h"
 #include <iterator>
 #include <set>
@@ -101,7 +102,7 @@ class po_iterator
 
   // VisitStack - Used to maintain the ordering.  Top = current block
   // First element is basic block pointer, second is the 'next child' to visit
-  std::vector<std::pair<NodeRef, ChildItTy>> VisitStack;
+  SmallVector<std::pair<NodeRef, ChildItTy>, 8> VisitStack;
 
   po_iterator(NodeRef BB) {
     this->insertEdge(Optional<NodeRef>(), BB);